“They’d need to growl and look menacing on command, I think, and carry back prey of one kind or another to their master. I assume they wouldn’t let them catch things on camera … especially fish, of course.”

Filming on season three of the television series has been taking place in South Africa but producers are due to start training the dogs as soon as possible for their appearance in the subsequent series, it is understood.

Rollo comes into the Outlander story after young Ian Murray meets him on the docks in North Carolina after winning him in a card game.

A spokesman for Starz, which produces the programme, said: “The dog will play a key part in the adventure that lies ahead.”